JPH05284604A - Current collecting material made of carbon/metal fiber composite material - Google Patents

Abstract

PURPOSE:To enhance abrasion resistance of current collecting material by composing the current collecting material of a carbon/metal fiber composite material and an organic lubricant. CONSTITUTION:A carbon/metal fiber composite material and a solid organic lubricant are arranged alternately at a sliding part. The organic lubricant includes simple substance of grease, lubricant oil, wax, etc., or a mixture thereof with an additive for imparting heat resistance, mechanical strength or conductivity. In order to provide sufficient conductivity through an insulation film of the organic lubricant, volumetric content of metal fiber in the carbon/metal fiber composite material is preferably set at 10 vol.% or above. According to the composition, abrasion resistance can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current collecting material composed of a carbon / metal fiber composite material suitable for use as a current collecting plate for a pantograph of an electric railway (hereinafter referred to as a sliding plate for a pantograph).

[0002]

2. Description of the Related Art A current collector such as a pantograph contact plate is required to have high conductivity, excellent wear resistance, and low consumption of trolley wire. Conventionally, carbon sintered bodies and hard copper have been used as current collector materials such as sliding plates for pantographs, but with the speeding up of electric railways, sintered alloys of copper, iron, carbon, etc. and carbon-metal composites have been used. A lot of wood is used. Conventional current collector materials such as pantograph contact plates are classified into metal-based materials and carbon-based materials from the viewpoint of lubrication during use. In metal-based current-collecting materials, solid lubricants such as grease, whose main component is wax, to which ethylene vinyl acetate and polyethylene wax are added to impart heat resistance and mechanical strength, and graphite has been added to provide some conductivity. It has been reported that the wear of the contact plate and trolley wire is reduced by using the above organic lubricant (RRR).
Magazine, 1990.6). On the other hand, in the case of a carbon-based current collecting material containing a metal-impregnated material obtained by pressure-impregnating a molten metal into a porous carbon material at high temperature, carbon itself is a good lubricant, so No need to use,
It is said that when an organic lubricant is used, abrasion powder and the like are adhered, and the wear of the current collecting material is increased. For this reason,
The use of grease and solid lubricants is avoided when using carbon-based contact strips in electric railways.

The carbon-based current collecting material is widely used because it has an excellent property that the mating material such as trolley wire is hard to be worn as compared with the metal-based current collecting material. There was a drawback that the abrasion resistance was poor. As a current collector material that eliminates the drawbacks of this carbon-based current collector material, a metal-impregnated carbon material obtained by pressure impregnation of a porous carbon material with molten metal, or a metal powder added to a carbon material raw material, and carbonized after molding Obtained by adding metal fibers to the raw material of carbon material, carbon material, and then carbonizing after molding (JP-A-62-72564, JP-A-62-197352), It was obtained by mixing metal powder and metal fibers into the entire carbon material raw material, adding carbon fiber to the sintered material and carbon material raw material after molding and changing the addition rate of the metal fiber depending on the position, and then carbonizing after molding. Carbon such as sintered materials
Metal composites are known.

[0004]

The above metal-impregnated materials have finely dispersed metal and have good wear resistance under arc discharge, but have low toughness and are subject to chipping or breakage due to the impact force generated during running. Has a drawback that it is apt to occur. Sintered materials containing metal powder have almost the same characteristics as metal-impregnated materials and have good wear resistance under arc discharge, but have low toughness and are damaged by the impact force generated during running. It has a drawback that it is easily broken or broken. Sintered materials added with metal fibers have improved toughness and plastic deformability, so that damage and breakage due to impact during running are significantly reduced, but metal fibers usually have a cross section of about 50 μm square or more and a long length. Is a few mm or more, which is significantly coarser than impregnated metal or metal powder, and the metal fibers elute due to the heat when the arc discharge occurs, and fiber-shaped voids are created in the trace, so the conditions under which arc discharge occurs There is a problem that the abrasion resistance is poor. Sintered materials, which are a mixture of metal powder and metal fibers, can reduce the amount of metal fibers added compared to the method of adding metal fibers, but the wear resistance at the time of arc discharge is significantly different from the method of adding metal fibers. There is no. This is presumed to be because there is no difference in the size of each defect caused by the elution of the metal fibers because the metal fibers are present in the sliding portion even if the amount of addition of the metal fibers is slightly reduced. In addition, for sintered materials with different metal fiber addition rates depending on the position, if the metal fiber content on the sliding surface side is reduced and the metal fiber content on the non-sliding surface side is increased, the sliding surface side Although the metal fiber content can be reduced, the wear resistance at the time of arc discharge is not so different from the method of adding the metal fiber for the same reason as the method of mixing the metal powder and the metal fiber throughout.

An object of the present invention is to maintain the high toughness and excellent impact resistance of the carbon / metal fiber composite material obtained by adding a metal fiber to a carbon material and molding and carbonizing the carbon material, thereby improving wear resistance. An object of the present invention is to provide a current collecting material composed of a carbon / metal fiber composite material having improved properties.

[0006]

[Means for Solving the Problems] The inventors of the present invention have conducted earnest test research on application of an organic lubricant used in a metal-based current collecting material to a carbon-based current collecting material in order to achieve the above object. It was As a result, it was clarified that when the carbon / metal fiber composite material and the organic lubricant are used in combination, the form and amount of the metal component in the carbon material have a great influence on the wear resistance of the current collector material under energization, This invention was reached.

That is, the present invention is a carbon / metal fiber composite current collecting material comprising a carbon / metal fiber composite material and an organic lubricant.

A carbon / metal fiber composite current collector in which a carbon / metal fiber composite material and a solid organic lubricant are alternately arranged at least in the sliding portion thereof.

[0009]

[Function] A pure carbon material containing no metal fibers, a metal-impregnated carbon material, or the like slides in the presence of an organic lubricant while being energized, and the organic lubricant having no conductivity causes the current collector material to slide. When an insulating film is formed between the moving surface and the mating material and a constant current is applied, the potential difference between them becomes large and a minute arc discharge occurs, causing the current collector material to wear when no organic lubricant is present. Instead, it becomes bigger. On the other hand, in the case of the current-collecting material comprising the carbon / metal fiber composite material and the organic lubricant in the present invention in which the metal fiber made of iron or copper is added, even if the organic lubricant is present, the fine arc discharge is generated. Does not occur,
The amount of wear of the current collecting material is significantly smaller than that in the case of no lubrication, and the amount of wear of the mating material is also reduced. The reason for this is not clear, but since metal fibers are present, when sliding while energized, the insulating film between the current collector sliding surface and the mating material formed of an organic lubricant that does not have electrical conductivity It is considered that the metal fibers protrude microscopically, penetrate the insulating film of the organic lubricant, and are electrically connected to the mating material, so that arc discharge is unlikely to occur.

As the organic lubricant in the present invention,
Grease, lubricating oil, wax, etc. alone or heat resistance,
It is possible to use a mixture of additives that impart mechanical strength and conductivity. The organic lubricant is used in combination with the carbon / metal fiber composite material as an organic lubricant applied to the surface of the carbon / metal fiber composite material, or the organic lubricant is applied to the internal pores of the carbon / metal fiber composite material. Or a carbon / metal fiber composite material and a solid organic lubricant are alternately arranged at least in the sliding part, and both slide on the mating material to form a carbon / metal fiber composite sliding surface. Various forms such as lubrication are possible.

As described above, the carbon / metal fiber composite material according to the present invention has a volume content of the metal fiber in the carbon / metal fiber composite material in order to provide sufficient conduction through the insulating film of the organic lubricant. The rate is preferably 10% by volume or more. When the volume content of the metal fibers in the carbon / metal fiber composite is less than 10% by volume, sufficient conductivity cannot be obtained when an organic lubricant is used in combination, and a fine arc discharge easily occurs. Increased wear of metal fiber composites. In the present invention, the material, shape, etc. of the metal fiber added to the carbon material are not particularly limited, but it is a metal fiber such as low carbon steel, copper, low carbon steel having a surface plated with copper, and a cross sectional area of
0 to 40,000 μm ² (10 to 200 μm square), length 1
Those having a thickness of 0 mm or less show good performance.

The carbon / metal fiber composite material according to the present invention can be produced by mixing a carbon material and a metal fiber, molding and carbonizing the mixture. As a molding method, various methods such as cold mold molding, CIP molding, and hot press molding are possible. The molded body obtained by these moldings can be made into a carbon / metal fiber composite material by carbonizing it by an ordinary carbonization method.

[0013]

EXAMPLES Example 1 Samples A to D having the compounding ratios shown in Table 1 were prepared and subjected to a molding experiment. The volume% of the blending ratio in Table 1 was obtained from the volume calculated by dividing the blending weight ratio of each raw material by the true specific gravity of the raw material.
As raw material, 50 μm square, length 3 mm, true specific gravity 7.8
6 mm mild steel steel fiber, regular grade petroleum coke carbonized at 1000 ℃, diameter 10 mm
Petroleum coke powder having an average particle size of 13 μm and a true specific gravity of 2.0 obtained by pulverizing for 4 hours in a vibration mill packed with stainless steel balls and a coal having a true specific gravity of 1.4 at a softening point of 250 ° C. by a flow tester method. Tar pitch was used.

As a molding die, an ordinary steel die having an inner diameter of 100 mm was used, and the raw materials were mixed in the proportions shown in Table 1. Then, only the weight of the finished thickness of 20 mm was charged to obtain a uniform thickness. Level and then 200 kg of this mold
While pressing at / cm ² , the heater was heated from the side by a heater to raise the temperature to 550 ° C at 10 ° C / min, and the temperature was maintained for 1.5 hours and then cooled to room temperature while being pressed. Thereafter, the molded body was taken out of the mold, placed in a stainless steel container filled with powdered coke, heated from room temperature to 1040 ° C. at 10 ° C./min in a nitrogen atmosphere, and held for 2 hours for carbonization,
The container was taken out into the atmosphere and cooled. The internal temperature of the container was cooled to 100 ° C in 4 hours.

[0015]

[Table 1]

The carbon / steel fiber composite materials obtained from each of the samples A to D were subjected to a wear test by using a sample E of metal-impregnated carbon impregnated with a copper alloy as a comparative material. The wear test is
A wear test piece is cut out from each carbon / steel fiber composite material and metal-impregnated carbon sample E, and a wear tester of a type that energizes while pressing the wear test piece against a rotating disk is used.
Abrasion test piece sliding surface size with copper disk as counter material:
10 mm x 10 mm, sliding speed: 100 km / Hr, current collection: DC80A, pressing force: 5 kgf, sliding time:
30 minutes, copper plate initial roughness: smooth (unused glossy surface, unused surface is used for each test) under the test conditions, all wear test pieces, when no lubricant is used and as grease (lubricant (Company, trade name: Epinox grease No. 1, for high speed) was tested in two cases where the wear test piece was applied to the sliding surface side, and the effect of lubrication on wear resistance was investigated. The results are shown in Table 2. The specific wear amount was calculated from the measured wear volume using the following formula. Specific wear amount = wear volume / pressing force / sliding distance

[0017]

[Table 2]

As shown in Table 2, the carbon-steel fiber composite materials obtained from Samples A to C show a remarkable decrease in specific wear amount when grease is applied. On the other hand, in the carbon / steel fiber composite material obtained from sample D having a small steel fiber content of 5% by volume and sample E which is metal-impregnated carbon, when lubricated with grease, a fine arc discharge occurred during sliding. , The specific wear amount is higher than that without lubrication. From this, 10% by volume of metal fiber
It is clear that in the carbon-steel fiber composite material of the present invention containing the above, in the presence of grease, the abrasion of the current collecting material at the time of energization is remarkably reduced as compared with the case without grease.

Example 2 Using a carbon / steel fiber composite material (steel fiber content 30% by volume) obtained from Sample B of Example 1 and Sample E of metal-impregnated carbon, grease was impregnated under reduced pressure to collect current. The effect on the wear resistance of the material was investigated. 3 test materials
The mixture was shaped into 0 mm × 30 mm × 15 mm, and the same grease as in Example 1 was used to heat the mixture to 220 ° C. under atmospheric pressure to dissolve the grease, and the pressure was reduced to 4 torr at 220 ° C., and then 220 ° C. to atmospheric pressure. After holding, it was cooled and impregnated under reduced pressure. The adhered grease of this grease-impregnated sample was wiped off well with a cloth, the surface was lightly polished, and a wear test under energization was carried out under the same conditions as in Example 1. The results are shown in Table 3.

[0020]

[Table 3]

As shown in Table 3, carbon obtained from sample B
The test material in which the steel fiber composite material was impregnated with grease had a wear resistance of 1 /
It is as small as 2.5 and wear resistance is greatly improved.

[0022]

As described above, the current collecting material comprising the carbon / metal fiber composite material and the organic lubricant of the present invention has remarkably excellent wear resistance, and when used as a sliding plate of a pantograph, it can be easily worn. The plate and trolley wire are not consumed much, and the effect is extremely large.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01B 1/04 7244-5G

Claims (2)

[Claims] 1. A current collecting material made of a carbon / metal fiber composite material comprising a carbon / metal fiber composite material and an organic lubricant. 2. A current collecting material made of a carbon / metal fiber composite material, wherein a carbon / metal fiber composite material and a solid organic lubricant are alternately arranged at least in a sliding portion thereof.